Grocery stores may be low on flour and yeast, but sourdough starter sellers are seeing huge increases in sales.

In November 2019, a tweet from comedy writer Ellory Smith went viral. "If someone you know is getting deeply into making bread from scratch they are deeply depressed I promise you," Smith wrote, with a response of nearly 250,000 likes as of this writing. Now, in our current state of collective isolation, anxiety, and sadness, Smith's tweet reads like a prophecy.

People aren't just making any old bread, though. If Twitter is any indication of what we're all doing while we're "working from home," it would seem that everyone has suddenly picked up sourdough, a more intensive and attention-needing type of bread baking:

Sourdough gets its leavening from a starter, a mixture of flour and water that becomes tart, squishy, and bubbly as it grows natural yeast. Like a pet, a starter—which is a living organism—must be "fed" regularly with flour and water (like a pet, it can also die). Obtaining a starter often spurs a sourdough baking habit, a hobby with near-cult like devotion. According to statistics provided to VICE by Reddit, the subreddit forum r/Sourdough, with 67,000 subscribers, has seen activity go up by over 170 percent since January 1.

You can make a starter from scratch, sure. But the process takes at least five days, according to King Arthur Flour, who recommends using all-purpose flour in addition to whole wheat or rye flours because the outside bran of whole grains has more nutrients and micro-organisms to kick off the growth of yeast. That said, all of those things might be hard to come by at the moment. Though many people have created sourdough starter by using portions of friends' starters, popping by a friend's house to grab a bit seems ill-advised during our time of social distancing.

The sudden rise of #stayhome sourdough bread baking prompts the question, then: Where is everyone getting their starter all of a sudden?

In San Francisco, some people might have recently obtained their sourdough starter because it was attached in small, individual bags to a telephone pole with a flyer stating that its name is "Godrick" and that he likes to be "kept warm and fed regularly." The flyer included a phone number to call if the starter ran out; however, the person behind the giveaway told VICE that out of an abundance of caution regarding potential virus transmission, the free starter on the telephone pole is no longer.

Most people probably aren't grabbing bubbly, sour yeast from a telephone pole, though. Baker Savannah Turley used to run sourdough workshops in New York before COVID-19 prompted restaurant closures that pushed her to move back to California. Turley told VICE that she's "definitely noticed more people baking since the shit hit the fan."

Turley is even sharing her starter. "I have just started dehydrating my starter to mail around and have about 20 orders already," she said. Starter can be dehydrated for ease of shipping and a less time-sensitive shelf-life, though it can also be shipped in its hydrated form. "I had already sent mostly ready starter to a couple friends and will begin teaching Zoom classes next week by donation."

For those who don't have a professional bread baker for a friend, however, Turley recommended asking local businesses, who might also be able to help out in the age of empty flour shelves.

"Local bakeries are also selling flour and will give starter away," Turley said. "I think almost everyone knows someone who knows someone who has a starter and it infinitely regenerates, so there is plenty to [go] around. She Wolf [Bakery] regularly gives starter away. I know C&B in the East Village is doing the same."

At Leo, a sourdough-focused pizzeria in Brooklyn, co-owner Mike Fadem estimated "definitely over an 100% increase" in requests for sourdough starter in the past two weeks. In the past, Fadem told VICE, it's been more like one request per month, but they got at least 10 just last week. Leo sells its starter—which Fadem's roommate first created 10 years ago, and which Fadem has continued feeding ever since—for two dollars, and they're working on adding it to their delivery menu as well.

And of course, people are also seeking starters out online. Comparing sales to last March, Chris Barton of the Etsy store ZOURDOUGHstarter told VICE in an email, "We're currently running a 400 percent increase." Barton attributed this rise in interest to the fact that store-bought yeast has quickly sold out since stores don't stock large quantities of it. As a result, and alongside the realization that homemade bread is possible when you're stuck in your house or apartment for weeks on end, Barton said, "People turned to the internet and found us."

According to Barton, Zourdough was "uniquely positioned to supply thousands of starter yeast packets worldwide." Having sold starter yeast online for 10 years, Zourdough had built up a large inventory of starter before the interest really hit, and it has a machine that can package 1,000 units in just four hours. Despite that, Barton said that they had to "pull back a bit" on sales recently due to short supply. "As of this Friday, we will release the bonds we put on our sales and let it fly. I think we can keep production and shipping going 24-7," Barton said.

MomsSanFranSourdough, which sells starter on Etsy and on eBay, has also experienced an increase in sales, telling VICE in a message, "Sales picked up slightly when COVID first made it to the States, but when California went under the [shelter-in-place order], sales skyrocketed. Since then, as the other states followed California’s example, sales have continued to increase."

While it might seem self-sufficient and appealing to create your own starter, Barton still thinks there's an upside to getting a more developed one: "You can make your own starter, but it will be weak and basically tasteless for about 5-7 years. We sell verified OLD starters. Most of them are well into their 100-year-old range, so once the home person activates it, they have what we have… a good, active, sour, producing starter."

As the Washington Post wrote, it's long been known that cooking and baking can help anxiety since it gives our antsy brains and bodies something to do. That's all the more relevant when all our hobbies outside the home aren't possible. Throw in the fact that we're all tethered to our devices and that our brains all want to follow suit with what everyone else is doing, and it's no surprise that the cult of sourdough is taking over our Twitter feeds. It might not be the worst hobby to start, though.

"It's an absolutely insane time and I'm just glad people are baking. The rhythm of it definitely helps from going stir crazy," Turley said. "People just need a straightforward thing to do that will nourish and entertain them. Luckily, sourdough does both those things."